From: Peter Zijlstra <peterz@infradead.org>
To: Christopher Lameter <cl@linux.com>
Cc: cmetcalf@mellanox.com, linux-kernel@vger.kernel.org,
tglx@linutronix.de, torvalds@linux-foundation.org, hpa@zytor.com,
riel@redhat.com, mingo@kernel.org, efault@gmx.de,
frederic@kernel.org, kernellwp@gmail.com,
paulmck@linux.vnet.ibm.com, lcapitulino@redhat.com,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags
Date: Mon, 30 Oct 2017 17:11:01 +0100 [thread overview]
Message-ID: <20171030161101.wprohopz5eg7snb4@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.DEB.2.20.1710301045160.970@nuc-kabylake>
On Mon, Oct 30, 2017 at 10:48:04AM -0500, Christopher Lameter wrote:
> On Fri, 27 Oct 2017, Peter Zijlstra wrote:
>
> > I _strongly_ object to this statement, isolcpus is _not_ the preferred
> > way, cpusets are.
> >
> > And yes, while cpusets suffers some problems, we _should_ really fix
> > those and not promote this piece of shit isolcpus crap.
>
> Well low level control at the processor level is important and this allows
> controlling activities on a processor that is supposed to be dedicated to
> certain activities without OS interaction.
>
> isolcpus is the *right* approach here because you are micromanaging the OS
> and are putting dedicated pieces of software on each core.
That is what you want, and cpusets should allow for that just fine.
> A cgroup suggests that threads would be scheduled over multiple cores
> which is *not* what you want.
No, that suggestion is false. cpusets should allow you to isolate
individual CPUs just fine.
> cgroup has to do something with containers
Sod containers. That's just modern group think. cpusets existed long
before all that wankery and it should very well retain the original use
cases.
That said, I know there's problems with cpusets, and those should be
fixed. But that doesn't mean isolcpus is anything other than a vile
hack.
next prev parent reply other threads:[~2017-10-30 16:11 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-27 2:42 [GIT PULL] Housekeeping subsystem v6 Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 01/12] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-10-27 12:01 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 02/12] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-10-27 12:02 ` [tip:sched/core] sched/isolation, " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-10-27 12:02 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 04/12] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: Make the " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 06/12] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-10-27 12:03 ` [tip:sched/core] sched/isolation: Rename is_housekeeping_cpu() to housekeeping_cpu() tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 07/12] housekeeping: Move it under its own config, independent from NO_HZ Frederic Weisbecker
2017-10-27 12:04 ` [tip:sched/core] sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-10-27 12:04 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 09/12] housekeeping: Handle the nohz_full= parameter Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 10/12] housekeeping: Move isolcpus to housekeeping Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: Move isolcpus= handling to the housekeeping code tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 11/12] housekeeping: Add basic isolcpus flags Frederic Weisbecker
2017-10-27 12:05 ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27 2:42 ` [PATCH 12/12] housekeeping: Document " Frederic Weisbecker
2017-10-27 12:06 ` [tip:sched/core] sched/isolation: Document the isolcpus= flags tip-bot for Frederic Weisbecker
2017-10-27 13:58 ` Peter Zijlstra
2017-10-27 14:36 ` Frederic Weisbecker
2017-10-27 17:06 ` Ingo Molnar
2017-10-27 17:33 ` Frederic Weisbecker
2017-10-27 18:21 ` Ingo Molnar
2017-10-27 18:39 ` Frederic Weisbecker
2017-10-27 19:04 ` Ingo Molnar
2017-10-27 14:38 ` Mike Galbraith
2017-10-30 15:48 ` Christopher Lameter
2017-10-30 16:11 ` Peter Zijlstra [this message]
2017-10-30 16:30 ` Christopher Lameter
2017-10-30 16:58 ` Peter Zijlstra
2017-10-30 16:56 ` Mike Galbraith
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